systole n.

word-forming element meaning "together with, jointly; alike; at the same time," also sometimes completive or intensive, from Greek syn (prep.) "with, together with, along with, in the company of," from PIE *ksun- "with" (source also of Russian so- "with, together," from Old Russian su(n)-). Assimilated to -l-, reduced to sy- before -s- and -z-, and altered to sym- before -b-, -m- and -p-. Since 1970s also with a sense of "synthetic."

Proto-Indo-European root meaning "to put, stand, put in order," with derivatives referring to a standing object or place.

It forms all or part of: apostle; catastaltic; diastole; epistle; forestall; Gestalt; install; installment; pedestal; peristalsis; peristaltic; stale (adj.); stalk (n.); stall (n.1) "place in a stable for animals;" stall (n.2) "pretense to avoid doing something;" stall (v.1) "come to a stop, become stuck;" stallage; stallion; stele; stell; still (adj.); stilt; stole (n.); stolid; stolon; stout; stultify; systaltic; systole.

It is the hypothetical source of/evidence for its existence is provided by: Greek stellein "to put in order, make ready; equip or dress with weapons, clothes, etc.; prepare (for a journey), dispatch; to furl (sails);" Armenian stełc-anem "to prepare, create;" Albanian shtiell "to wind up, reel up, collect;" Old Church Slavonic po-steljo "I spread;" Old Prussian stallit "to stand;" Old English steall "standing place, stable," Old High German stellen "to set, place."